10 Jun
2021
10 Jun
'21
1:35 p.m.
Hello list!
I am on (K)Ubuntu Studio 20.04) and needed a couple of extra in- and
outputs, so I connected 2 USB audio interfaces to my computer (a
FocusRite Scarlett 2i4 and an Edirol UA-25ex - they're old, but reliable
devices).
Through Studio Controls I set the Scarlett as master device and started
Jack, then I experienced recording and playback with Ardour in (as far
as I can hear) perfect sync.
I was amazed at the ease of this setup and the problem-free routing of
audio signals, so just for testing I split a stereo source recording one
channel on each device to one stereo track in Ardour. To my ears, the
sync is still perfect.
However, from this article
https://jackaudio.org/faq/multiple_devices.html it seems I have to
expect sync problems over time unless I do some manual configuring using
the alsa_in and alsa_out clients.
Is this still valid?
10 Jun
10 Jun
1:48 p.m.
An (easier) alternative is to use zita-j2a (zita-a2j for input), I'm
surprised that's not even mentioned on that page. It takes care of the
resampling when clocks drift.
On 10.06.21 11:35, Alf Haakon Pietruszka Lund wrote:
Hello list!
I am on (K)Ubuntu Studio 20.04) and needed a couple of extra in- and
outputs, so I connected 2 USB audio interfaces to my computer (a
FocusRite Scarlett 2i4 and an Edirol UA-25ex - they're old, but reliable
devices).
Through Studio Controls I set the Scarlett as master device and started
Jack, then I experienced recording and playback with Ardour in (as far
as I can hear) perfect sync.
I was amazed at the ease of this setup and the problem-free routing of
audio signals, so just for testing I split a stereo source recording one
channel on each device to one stereo track in Ardour. To my ears, the
sync is still perfect.
However, from this article
https://jackaudio.org/faq/multiple_devices.html it seems I have to
expect sync problems over time unless I do some manual configuring using
the alsa_in and alsa_out clients.
Is this still valid?
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
https://lists.linuxaudio.org/listinfo/linux-audio-user
1:53 p.m.
Oh, Only read now about alsa_in and alsa_out. TIL!
Anyone knows how they compare to zita-j2a and zita a2j?
On 10.06.21 11:47, Max wrote:
An (easier) alternative is to use zita-j2a (zita-a2j
for input), I'm
surprised that's not even mentioned on that page. It takes care of the
resampling when clocks drift.
On 10.06.21 11:35, Alf Haakon Pietruszka Lund wrote:
Hello list!
I am on (K)Ubuntu Studio 20.04) and needed a couple of extra in- and
outputs, so I connected 2 USB audio interfaces to my computer (a
FocusRite Scarlett 2i4 and an Edirol UA-25ex - they're old, but
reliable devices).
Through Studio Controls I set the Scarlett as master device and
started Jack, then I experienced recording and playback with Ardour in
(as far as I can hear) perfect sync.
I was amazed at the ease of this setup and the problem-free routing of
audio signals, so just for testing I split a stereo source recording
one channel on each device to one stereo track in Ardour. To my ears,
the sync is still perfect.
However, from this article
https://jackaudio.org/faq/multiple_devices.html it seems I have to
expect sync problems over time unless I do some manual configuring
using the alsa_in and alsa_out clients.
Is this still valid?
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
https://lists.linuxaudio.org/listinfo/linux-audio-user
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
https://lists.linuxaudio.org/listinfo/linux-audio-user 
2:46 p.m.
On Thu, Jun 10, 2021 at 11:53:32AM +0200, Max wrote:
Oh, Only read now about alsa_in and alsa_out. TIL!
Anyone knows how they compare to zita-j2a and zita a2j?
Simple answer: badly. This is why I wrote zita-a2j/j2a
in the first place. If you want reliable resuls, use those.
Jack1 (via the -A option) has them built-in, but these
are probably based on an old release of the original and
not updated.
Whatever you use, there will always be a delay difference
between the main soundcard used by Jack and the added one(s).
At least with the zita tools this will be defined and stable,
so you can measure and then compensate for it. In many cases
it won't matter much as long as you don't split a stereo signal
over two interfaces.
BTW, the page on the jack wiki pointed to earlier is
completely out of date. Just ignore whatever is said
there.
Ciao,
--
FA
3:29 p.m.
On 10.06.2021 12:46, Fons Adriaensen wrote:
Whatever you use, there will always be a delay
difference
between the main soundcard used by Jack and the added one(s).
At least with the zita tools this will be defined and stable,
so you can measure and then compensate for it. In many cases
it won't matter much as long as you don't split a stereo signal
over two interfaces.
BTW, the page on the jack wiki pointed to earlier is
completely out of date. Just ignore whatever is said
there.
Could (or should) Studio Controls start zita automatically when
connecting more than one soundcard? There's a setting in Studio Controls
'Bridge USB devices to jack when plugged in' that's on by default and
maybe does exactly that.
But if so, it's not clear from the dialog whether this is done via zita
or other measures. The manual at
https://ovenwerks.github.io/studio-controls/extra-devices.html doesn't
say this either, but the overview at
https://ovenwerks.github.io/studio-controls/index.html states that
Studio Controls "Allows multiple audio devices to use JACK at once".
So far my humble testing confirms that, for which I'm very grateful.
Alf
6:15 p.m.
On Thu, June 10, 2021 6:29 am, Alf Haakon Pietruszka Lund wrote:
Could (or should) Studio Controls start zita
automatically when
connecting more than one soundcard?
It does.
But if so, it's not clear from the dialog whether
this is done via zita
or other measures. The manual at
https://ovenwerks.github.io/studio-controls/extra-devices.html doesn't
say this either,
The manual does say very explicitly.
From the first sentence on that link you provided:
"The Extra Devices tab allows other audio devices in the system to show up
as JACK clients and be used by JACK applications. These bridges are
created using zita-ajbridge a light weight but high quality bridge. These
bridges use resampling to make sure the audio is in sync with the master
audio device. "
The package zita-ajbridge includes the individual clients zita-a2j and
zita-j2a for alsa-to-jack and jack-to-alsa bridging respectively.
--
Chris Caudle
6:51 p.m.
On 10.06.2021 16:15, Chris Caudle wrote:
On Thu, June 10, 2021 6:29 am, Alf Haakon Pietruszka
Lund wrote:
OUCH! Even if linking to it, I didn't manage to properly RTFM...
Guess my multitasking skills took a blow today. Thanks for setting me
straight :-D
Best regards,
Alf
Could (or should) Studio Controls start zita
automatically when
connecting more than one soundcard?
It does.
But if so, it's not clear from the dialog
whether this is done via zita
or other measures. The manual at
https://ovenwerks.github.io/studio-controls/extra-devices.html doesn't
say this either,
The manual does say very explicitly.
From the first sentence on that link you provided:
"The Extra Devices tab allows other audio devices in the system to show up
as JACK clients and be used by JACK applications. These bridges are
created using zita-ajbridge a light weight but high quality bridge. These
bridges use resampling to make sure the audio is in sync with the master
audio device. " 
6:38 p.m.
New subject: RME HDSPe AIO pro
Dear all,
I’ve been using HDSPe AIO cards with good succes for years (and contributed to fixing an
ADAT issue with the linux driver some time ago), but the most recent one I bought, seems
to be a new model named AIO PRO. The AIO PRO is not recognized by the (5.8.0-53) driver.
Is anyone working already on linux kernel driver support for the new RME HDSPe AIO PRO ?
Thanks and best,
Philippe.
Philippe BEKAERT
Hasselt University - Expertise center for Digital Media
Wetenschapspark 2, 3590 Diepenbeek, Belgium
www.edm.uhasselt.be
6:33 p.m.
On Thu, 10 Jun 2021, Alf Haakon Pietruszka Lund wrote:
Hello list!
I am on (K)Ubuntu Studio 20.04) and needed a couple of extra in- and
outputs, so I connected 2 USB audio interfaces to my computer (a
FocusRite Scarlett 2i4 and an Edirol UA-25ex - they're old, but reliable
devices).
Through Studio Controls I set the Scarlett as master device and started
Jack, then I experienced recording and playback with Ardour in (as far
as I can hear) perfect sync.
I was amazed at the ease of this setup and the problem-free routing of
audio signals, so just for testing I split a stereo source recording one
channel on each device to one stereo track in Ardour. To my ears, the
sync is still perfect.
However, from this article
https://jackaudio.org/faq/multiple_devices.html it seems I have to
expect sync problems over time unless I do some manual configuring using
the alsa_in and alsa_out clients.
Studio-controls already does this for you except it uses zita-ajbridge
instead of alsa_in/out for better quality and less cpu use.
However, I would still not split a stereo source over two devices. It is
likely that the stereo image will wander some even though the two channels
are "in sync". So long as there is some isolation between the two mics
there should be no problem but a set of mics for one instrument (like a
drumset for example) should all be on the same audio interface. So using
more than one USB mic for podcasting should be fine. For recording a "live
in the studio band" a single audio device or two connected with wordclock
are still better.
In the end, often you use what you have and as it sounds good to you, that
is what matters. A look to the future as equipment is replaced would see
an audio device with a larger number of inputs and preamps.
--
Len Ovens
www.ovenwerks.net
6:57 p.m.
On 10.06.2021 16:33, Len Ovens wrote:
On Thu, 10 Jun 2021, Alf Haakon Pietruszka Lund
wrote:
I did that just as a for-fun test, definitely will get bigger number of
i/o for bigger recordings.
Still amazed at how smoothly this just works.
Thanks for answering, and for programming!
Best regards,
Alf
I was amazed at the ease of this setup and the
problem-free routing of
audio signals, so just for testing I split a stereo source recording
one channel on each device to one stereo track in Ardour. To my ears,
the sync is still perfect.
However, from this article
https://jackaudio.org/faq/multiple_devices.html it seems I have to
expect sync problems over time unless I do some manual configuring
using the alsa_in and alsa_out clients.
Studio-controls already does this for you except it uses zita-ajbridge
instead of alsa_in/out for better quality and less cpu use.
However, I would still not split a stereo source over two devices. It is
likely that the stereo image will wander some even though the two
channels are "in sync". So long as there is some isolation between the
two mics there should be no problem but a set of mics for one instrument
(like a drumset for example) should all be on the same audio interface.
So using more than one USB mic for podcasting should be fine. For
recording a "live in the studio band" a single audio device or two
connected with wordclock are still better.
1296
days inactive
1296
days old
linux-audio-user@lists.linuxaudio.org
9 comments
6 participants
participants (6)
-
Alf Haakon Pietruszka Lund -
Chris Caudle -
Fons Adriaensen -
Len Ovens -
Max -
Philippe BEKAERT